The present invention relates to a process for increasing the molecular weight of chlorine-containing elastomers by the addition of sulphur compounds before or during the chlorination reaction and to elastomers produced thereby.
Because of solubility problems, the chlorination of polyolefins in solution necessitates the use of polyolefins of relatively low molecular weight. Accordingly, the products obtained frequently have viscosities (measured as the Mooney viscosity) which are too low for technical applications, and the crosslinking with peroxides of, for example, chlorinated polyethylenes such as these gives vulcanisates having unsatisfactory physical properties.
Consequently, there is a need in the art for chlorinated elastomers which have sufficiently high Mooney viscosities and the vulcanisates of which show satisfactory physical properties.